Administrators had to scramble to find substitute teachers today after 342 teachers called in sick.

The “sickout” came amid contract negotiations between the teachers and the Boulder Valley School District.

The district said six out of 54 schools were affected by the sickout: Boulder, Fairview and Centaraus high schools, along with Flatirons, University Hill Central Boulder and Sanchez elementary schools.

Administrators say they were able to fill many of the absences, yet they were unable to find substitutes for 118 of the vacancies. They say they combined some classes and used substitute teachers and administrators with classroom experience to fill the void.

Officials say they have about 2,100 teachers in the district. They plan to have subs ready to go Tuesday, but there’s no word on whether another sickout is planned.

On Friday, 60 out of 84 Broomfield High School teachers called in sick after their union failed to reach a contract agreement with the Boulder Valley School District.